Thermal switch



Jan. Z5, 1927-.

Original Fil@d Feb. lO. 1922 1,615,582 HAwKlNs THERMAL SWITCH 2 Sheets-Sheet 1 H. c. HAwKlNs THERMAL swITcH Jan. 25, 1927. y 1,615,582

original Filed Feb. 1o. 1922 2 sheets-sheet a f6 f1/4 Z374* grumpy fo@ Patented Jan. 25, 1927.

UNITE- STATES PATENT OFFICE.

HUBERT GHILDRESS HAWKINS, OF XVINSTO'N-SALEM', NORTH CAROLINA.

THERMAL SWITCH.

Application filedfl'ebruary 10, 1922, Serial This invention aims to provide a simple but effective means whereby a signal may be sounded, responsive. to a rise of temperature, the device being of peculiar util'.` `ty for signalling when a ire starts in a building.

The preferred embodiment ot the invention is shown, but a mechanic may make changes therein, Within the scope of 'what is claimed, Without departing from the spirit ot the invention or avoiding the charge ot infringement.

In the drawing z-Figure 1 shows in perspective, a device constructed in accordance with the invention, mounted in the ceiling ot an apartment; Figure 2 is an elevation vwherein parts are broken away, and sectioned; Figure 3 is a vertical section on the line 3.0i Figure-25 Figure 4 is a bottoni plan; Figure 5. is a section on the line of Figure 2; Figure 6 is a diagram showing the circuits which may be used.

The numeral 1 denotes an apartment coniprising a ceiling 2, a fioor 3 thereabove, and joists 4 between the ceiling` and the floor. A register 5 is attached by securing elements 6 to the ceiling 2 and includes a tubular neel; 7 projecting through the ceiling.

A back plate 8 is provided, andA a casing 9 is mounted on the back. plate, the parts 8 and 9 constituting a support, the bach plate being` held on one of the joists 4 by securing devices 10. The casing 9 has side tianges 11 through Which pass securing members 12 engaging the back plate 8, the casing 9 thus being held on the back plate. The casing 9 is open at its bottom, as shown at 14, and includes a top 15. A partition 16 extends across the casing 9 and is spaced from the top to form a compartment 17. Spaced tubes 18 are located in the casing 9 and are closed at their lower ends, the upper ends of the tubes being connected to the partition 16, the partition having openingsi19 which establish communication between the tubes and the compartment 17. 'lhc tubes 18 and the compartment 17 form un air chamber.

The device includes a conduit. denoted generally by the numeral 2O and including an inverted U-shaped part 21, which may be made of metal, a hand *valve 22 being interposed in the part or pipe 21. One end of the pipe 21 is connected to the top 15 of the casing 9 and communicates with the compartment 1,7. The other end of the pipe No. 535,567'. Renewed November 13, 1926.

21 extends downwardly and is connected by a coupling 24 to a tube 23, the tube preieraoly being made of glass or some other material which is neither an electrical conductor nor subject to attack by mercury or acid. A clip 25 is disposed beneath the coupling 24 and holds the tube 23 on the back plate 8. The numeral 26 marks a U- shaped' pipe which may be made ot metal, one end ot the said pipe being connected by a coupling 27 to the tube`23, the other end ci the pipe 26 being connected by av coupling 28 to a tube 29, which may be made of glass. the upper end of the tube 29 being closed by a cap 30. Clips 31, located adjacent to the cap 30 and the coupling 28, hold the tube 29 on the back plate 8. The parts 28, 26 and 29 may be described as a U-sl'iaped portion of the conduit which is denoted generally by the numeral 20. A conducting liquid 48, which may be mercury or any other suitable substance. stands in the parts 26, 25? and 29 oi: the conduit. Terminals 3 are mounted in the tube 23 and cooperate with the conducting liquid 48, the terminals being spaced vertically. Conductors 33 lead trom the terminals 32 to binding posts 34 on the back plate 8. Vertically spaced terminals the tube 29 and cooperate with the conducting, liquid the terminals 35 beingl connected by conductors 36 with binding'posts 37 on the back plate 8. The metallic pipe 26 of the conduit 2O carries a binding post 38.

A conductor 39 is connected to the binding post 38, a battery 40, or other source or' electrical energy, being interposed in the conductor 39. The ninneral 41 marks a conductor, one end et which is connected to the conductor 39, the other end ot the conductor 41 being adapted to be mounted in any of the binding posts 34. A relay 42 is interposed in the conductor 41 and is adapted to close an open circuit 43, including a source 44 o'' electrical energy. A. signal 45 is interposed in tbe circuit o. One end ot a conductor 46 is connected to the conductor 39, the other end ot the coniductor 46 being adapted to be mounted in any of the binding posts 37. A signal 48, such as a drop annunciator, is interposed in the conductor 46. If desired, the signal 47 may be placed in the lobb of a hotel, the register 5, the casing 9 an attendant parts being located in a guest room, and the sig- 35 are mounted in ii nal fl being:r placed. in a hose house, the ottice o'l a lire marshaly or in some other similar place.

Under ordinary temperatures, the conductingliquid d8 is in Contact with the terminals 32 and the metallic part 2G ot the conduit 20. rihen there is established a closed circuit comprising' the liquid 48 the pipe Q6, the lnndine` post 3S, the conductor 29, the conductor li` one of the bindinggl posts 3l, the corresponding conductor 323, the adjacent terminal and the liquid l-S. Likewise under ordi try teniperaturos7 the conducting liquid i8 is not in Contact with any ot' the tern'iinals 35, the device including, therefore, an open circuit including the liquid 4S, the pipe 2G, the binding post 3S, the conductor 39, the conductor (3, one ot the binding posts 3T, the corresponding c0nductor 8G, and the aljacent termnal 85.

Willen lire occurs, the air in the tribes 1S and the compartment 17 expandT pressure being` transmitted to the conduit 20, the conducting` liquid 48 being' Vtoreezl downwardly in the tube Q3 and upnardlj.r in the tube 29, the liquid moving out of contact with the terminal 32 Wheren'ith the conductor il connected, the liquid meting into contact With the terminal W @o Whereunto the conductor e6 is connected. rEhe result is that the circuit ot which the conductor lll is a part is opened7 the circuit of which the conductor '-lG is a part being closed. lllhen the circuito't which the conductor #il is a part is opened7 the relay l2 closes the signal circuit 43, and the signal is sounded. When the signal ot which the conductor -l is a part is closedj the il? is operated. Thus, both the clerk in a hotel, and a tire marshal or engine house attendant may be admonished that a Ere has started in the apartment l.

The Valve Q2 may be Closed in order to prevent the conducting lquid t8 trom running` back into the compartment l@ and the tubes 18, during the shipment` installation or repairing of the device. Since the conthat the conductor 46 may be connected to` any of the vertically spaced terminals S5 by Way ot' the binding posts 3T and he conductors 36, the signals 415 and i-T may be f made to operate at dilerent temperatures existing' in the apartment i.. Since a plurality ot the tubes 18 are rn'tn'ided and because these tubes are spaced apart1 a inattiinum arca is presented to the snperheziuted air in the zqartment lt and the derice is caused to be quickly and delicately esponsive to temperature changes.

That is claimed is l. In a device ot the cles-is described, :i easing open at one end and provided :it its other end with a compartment; a pli!- rality oit tubes in the c sind., the tubesI coinmunicating at one end vwith the compartment, each tube bei the tubes being spaced apart transversely; av conduit connnunicating` with the cor-,inuit`M ment; a conducting" liquid in the conduit; and a terminal in the conduit and cooperatng with the liquid` the open end of the casing- Serving to admit heeted air to tl tubes, the casing` serving to retain the air about the tubes, the plurality ot tul es and the compartment presentingY a large area to the heated air thereby to cause the conducting liquid to move rapidly and sensi 'rely `li respect to the terminal.

2. rEhe combination with the Wall ot a room7 of a casing mounted in the Wall and open at one end to comnninicate with the room` the casing' beingv provided with inten nal means ttor confiningair, a eondut coinmunieating' with said means, a cond" liquid in 'the conduit7 and a termina conduit and cooperatingl with 'nie l'e In testimony that l claim the toreygoine ny own, l have hereto inlined my signature.

CHELDRESS HAWK-S,

closed at its other end` 

